ios6 - Create a book shelf by using UICollectionView -

i'm going create book shelf in 1 of projects. basic requirement follows:

• similar ibooks bookshelf
• supports both orientations well
• supports kinds of ios devices (different resolutions)
• supports deleting , inserting items
• supports reordering of items long press gesture
• shows hidden logo when first row pulled down

the uicollectionview first option occurred me. supports grid cells. googled , found useful tutorials:

bryan hansen's uicollectionview custom layout tutorial

mark pospesel's how add decoration view uicollectionview

lxreorderablecollectionviewflowlayout

and here result: (please ignore color inconsistency problem because of graphics chose not perfect yet.)

what did:

1. created custom layout creating class inherited lxreorderablecollectionviewflowlayout (for reordering purposes) inherited uicollectionflowlayout
2. added decoration view showing logo
3. added decoration view showing bookshelfs

but ran few problems:

1. can't scroll @ if items can shown in 1 screen

then added following code, make contentsize bigger

- (cgsize)collectionviewcontentsize {     return cgsizemake(self.collectionview.bounds.size.width,      self.collectionview.bounds.size.height+100); } 

then can scroll now. here pull down first row:

you can see the decoration view logo working.

2. got second set of problems when pull last row:

you can see decoration view not added @ green box part.

3. background of decoration view bookshelf getting darker , darker. (please refer same problem here

4. book shelf bar moves when reorder items

i list of important code here:

- (void)preparelayout {     // call super flow layout can math cells, headers, , footers     [super preparelayout];      nsmutabledictionary *dictionary = [nsmutabledictionary dictionary];     nsmutabledictionary *shelflayoutinfo = [nsmutabledictionary dictionary];      // decoration view - emblem     nsindexpath *indexpath = [nsindexpath indexpathforitem:0 insection:0];     uicollectionviewlayoutattributes *emblemattributes =         [uicollectionviewlayoutattributes layoutattributesfordecorationviewofkind:[emblemview kind]             withindexpath:indexpath];     emblemattributes.frame = [self frameforemblem:yes];     dictionary[[emblemview kind]] = @{indexpath: emblemattributes};      // calculate shelves go in vertical layout     int sectioncount = [self.collectionview numberofsections];      cgfloat y = 0;     cgfloat availablewidth = self.collectionviewcontentsize.width - (self.sectioninset.left + self.sectioninset.right);     int itemsacross = floorf((availablewidth + self.minimuminteritemspacing) / (self.itemsize.width + self.minimuminteritemspacing));      (int section = 0; section < sectioncount; section++)     {         y += self.headerreferencesize.height;         //y += self.sectioninset.top;          int itemcount = [self.collectionview numberofitemsinsection:section];         int rows = ceilf(itemcount/(float)itemsacross)+1; // add 2 more empty row doesn't have data         (int row = 0; row < rows; row++)         {             indexpath = [nsindexpath indexpathforitem:row insection:section];             shelflayoutinfo[indexpath] = [nsvalue valuewithcgrect:cgrectmake(0,y, self.collectionviewcontentsize.width, self.itemsize.height + decoration_height)];             y += self.itemsize.height;              if (row < rows - 1)                 y += self.minimumlinespacing;         }          y += self.sectioninset.bottom;         y += self.footerreferencesize.height;     }      dictionary[[shelfview kind]] = shelflayoutinfo;      self.shelflayoutinfo = dictionary; }   - (nsarray *)layoutattributesforelementsinrect:(cgrect)rect {     nsarray *attributesarrayinrect = [super layoutattributesforelementsinrect:rect];      // cell layout info     (bookshelflayoutattributes *attribs in attributesarrayinrect)     {          attribs.zindex = 1;         catransform3d t = catransform3didentity;         t = catransform3dtranslate(t, 0, 0, 40);         attribs.transform3d = catransform3drotate(t, 15 * m_pi / 180, 1, 0, 0);     }      // add our decoration views (shelves)     nsmutabledictionary* shelfdictionary = self.shelflayoutinfo[[shelfview kind]];     nsmutablearray *newarray = [attributesarrayinrect mutablecopy];      [shelfdictionary enumeratekeysandobjectsusingblock:^(id key, nsvalue* obj, bool *stop) {          if (cgrectintersectsrect([obj cgrectvalue], rect))         {             uicollectionviewlayoutattributes *attributes = [uicollectionviewlayoutattributes layoutattributesfordecorationviewofkind:[shelfview kind] withindexpath:key];             attributes.frame = [obj cgrectvalue];              nslog(@"decorationview rect = %@",nsstringfromcgrect(attributes.frame));             attributes.zindex = 0;             //attributes.alpha = 0.5; // screenshots             [newarray addobject:attributes];         }     }];      attributesarrayinrect = [nsarray arraywitharray:newarray];      nsmutabledictionary* emblemdictionary = self.shelflayoutinfo[[emblemview kind]];     nsmutablearray *newarray2 = [attributesarrayinrect mutablecopy];     [emblemdictionary enumeratekeysandobjectsusingblock:^(nsindexpath *indexpath, uicollectionviewlayoutattributes *attributes, bool *innerstop) {         if (cgrectintersectsrect(rect, attributes.frame)) {             [newarray2 addobject:attributes];         }     }];      attributesarrayinrect = [nsarray arraywitharray:newarray2];      return attributesarrayinrect; } 

i'll appreciate if you're patient enough read post , provide advice or suggestions. , i'll post complete source code if can fix issues. thank in advance.

my advice , suggestion need check last row , [self.collectionview scrollenable:no] same first row, set background color clear of collectionview , collectionviewcell , bookshelf image set on background view.